We demonstrate novel nanohybrids of indium- and ruthenium-doped SnO2nanoparticles (NPs) on a reduced graphene oxide (RGO) surface prepared using a simple one-pot method at a relatively low temperature. The size of the doped SnO2 NPs on the RGO is as small as 2–3 nm with uniform distribution. We find that the introduction of dopants facilitates the NP nucleation on graphene oxide. The gas sensing responses of the resulting nanohybrids demonstrate that the addition of indium in SnO2 significantly enhances the sensitivity to NO2 compared with RGO–SnO2. The sensor also shows excellent selectivity to NO2 when other common gases such as NH3, H2, CO and H2S, are present. The sensing mechanism responsible for the superior sensitivity and selectivity of the nanohybrids is also discussed.